Deciphering Epiphreatic Conduit Geometry from Head and Flow Data

Abstract

Karst aquifers are hydraulic structures where dissolution conduits dictate complex spatial and temporal flow patterns. These aquifers are vertically divided into phreatic, epiphreatic and vadose zones. While the phreatic zone is permanently saturated, providing the major contribution to base flow, most of the flood event water is transferred through the epiphreatic zone. The spatial distribution of conduits within karst aquifers is largely unknown. The only technique giving accurate results is direct human exploration, although some limited information can be obtained from hydrograph analyses in springs and wells, through hydraulic tomography and by geophysical surveys.